Effects of Ligands in Novel Non-titanocene on Syndiotactic Polymerization of Styrene

ＩｎｔｒｏｄｕｃｔｉｏｎＳｙｎｄｉｏｔａｃｔｉｃｐｏｌｙｓｔｙｒｅｎｅ（ｓＰＳ）ｉｓａｈｉｇｈｌｙｃｒｙｓｔａｌｉｎｅｐｏｌｙｍｅｒｗｉｔｈａｍｅｌｔｉｎｇｔｅｍｐｅｒａｔｕｒｅｏｆａｂｏｕｔ２７０℃ａｎｄａｇｌａｓｓｔｒａｎｓｉｔｉｏｎｔｅｍｐｅｒ...     

聚碳酸亚丙酯洗涤工段洗涤液组分分析

采用气质联用法对聚碳酸亚丙酯（PPC）生产工艺中洗涤工段洗涤液组分进行定性及定量分析。分析结果表明洗涤液中的杂质主要有1-甲氧基-2．丙醇、2-甲氧基-1-丙醇、碳酸二甲酯、二丙撑二醇、碳酸丙烯酯。1次洗涤液中含环氧丙烷32．34％,含甲醇58．74％;4次洗涤液中含环氧丙烷10．61％,含甲醇89．01％。随着洗涤次数的增加,样品中环氧丙炕含量减小,甲醇含量增大。     

1,4,7,10-tetramethyl-5,6-didehydrodibenzo[a,e]cyclooctene. A presumably planar fully conjugated eight-membered ring compound.

The first known stable crystalline derivative of 5,6-didehydrodibenzo[a,e]cyclooctene (1), namely, 1,4,7,10-tetramethyl-5,6-didehydrodibenzo[a,e]cyclooctene (2), was prepared and unequivocally characterised.     

纳米级β-Ni(OH)2掺杂Al(OH)3的电化学性能

钠米粉体;纳米级β-Ni(OH)2掺杂Al(OH)3的电化学性能     

关闭—启动型Geom／G／1离散排队及其在ATM网络中的应用

研究带有关闭延迟和启动时间的Geom/G/1离散时间排队,导出了稳态队长、等待时间的分布及其随机分解结果,该模型可用于ATM网络的虚通道分析,给出响应时间、启动率,闲置率等指标公式。     

Matching Realization of Uq（sln＋1） of Higher Rank in the Quantum Weyl Algebra Wq（2n）

In the paper, we further realize the higher rank quantized universal enveloping algebra Uq（sln＋1） as certain quantum differential operators in the quantum Weyl algebra Wq （2n） defined over the quantum divided power algebra Sq（n） of rank n. We give the quantum differential operators realization for both the simple root vectors and the non-simple root vectors of Uq（sln＋1）. The nice behavior of the quantum root vectors formulas under the action of the Lusztig symmetries once again indicates that our realization model is naturally matched.     

Sieving polymer synthesis by reversible addition fragmentation chain transfer polymerization

Replaceable sieving polymers are the fundamental component for high‐resolution nucleic acids separation in CE. The choice of polymer and its physical properties play significant roles in influencing separation performance. Recently, reversible addition fragmentation chain transfer (RAFT) polymerization has been shown to be a versatile polymerization technique capable of yielding well‐defined polymers previously unattainable by conventional free‐radical polymerization. In this study, a high molecular weight poly‐(N,N‐dimethylacrylamide) (PDMA) at 765 000 gmol^?1 with a polydispersity index of 1.55 was successfully synthesized with the use of chain transfer agent—2‐propionic acidyl butyl trithiocarbonate in a multistep sequential RAFT polymerization approach. This study represents the first demonstration of RAFT polymerization for synthesizing polymers with the molecular weight range suitable for high‐resolution DNA separation in sieving electrophoresis. Adjustment of pH in the reaction was found to be crucial for the successful RAFT polymerization of high molecular weight polymer as the buffered condition minimizes the effect of hydrolysis and aminolysis commonly associated with trithiocarbonate chain transfer agents. The separation efficiency of 2‐propionic acidyl butyl trithiocarbonate PDMA was found to have marginally superior separation performance compared to a commercial PDMA formulation, POP?‐CAP, of similar molecular weight range.     

Double‐Shelled C@MoS2 Structures Preloaded with Sulfur: An Additive Reservoir for Stable Lithium Metal Anodes

The growth of Li dendrites hinders the practical application of lithium metal anodes (LMAs). In this work, a hollow nanostructure, based on hierarchical MoS₂ coated hollow carbon particles preloaded with sulfur (C@MoS₂/S), was designed to modify the LMA. The C@MoS₂ hollow nanostructures serve as a good scaffold for repeated Li plating/stripping. More importantly, the encapsulated sulfur could gradually release lithium polysulfides during the Li plating/stripping, acting as an effective additive to promote the formation of a mosaic solid electrolyte interphase layer embedded with crystalline hybrid lithium‐based components. These two factors together effectively suppress the growth of Li dendrites. The as‐modified LMA shows a high Coulombic efficiency of 98 % over 500 cycles at the current density of 1 mA cm^?2. When matched with a LiFePO₄ cathode, the assembled full cell displays a highly improved cycle life of 300 cycles, implying the feasibility of the proposed LMA.     

Absorption Spectra of the 4f Electron Transitions of the Nd, Ho and and Er Complexes with 1-Cyclopyropyl-6-fluoro-1,4-dihydro-7- (4-ethyl-1-piperazinyl)-4-oxo-3-quinoline Carboxylic Acid Hydrochloride in the Presence of TX-100

The tripositive rare earth metal ions show comparatively little tendencies to form complexes with a variety of normally powerful coordinating agents due to their peculiar electronic configurations. However, certain chelating groups, notably the β-diketones1,2 and 8-quinolinols3,4, are capable of overcoming this difficulty through the formation of inner complex compounds. 1-Cyclopropyl-6-fluoro-1,4-dihydro-7-(4-ethyl-1-piperazinyl)-4-oxo-3-quinoline carboxylic acid hydrochloride (NN…